Tuesday, March 10, 2015

Researchers have published the first comprehensive analysis of the gut bacteria found in queen honey bees (Apis mellifera), and they’ve found that the microbiomes of queens are very different from worker bee microbiomes.

“In many animals, transmission of the microbiome is maternal,” said co-author Irene L.G. Newton, assistant professor of biology at the University of Indiana. “In the case of the honey bee, we found that the microbiome in queen bees did not reflect those of worker bees — not even the progeny of the queen or her attendants. In fact, queen bees lack many of the bacterial groups that are considered to be core to worker microbiomes.”

The study’s results, which are published in the journal Applied and Environmental Microbiology, are the opposite of microbiome development in many mammals, in which infants’ microbiomes are influenced by their mothers. Human babies delivered through natural birth possess microbiomes similar to those found in their mother’s birth canal, for example, while babies born through cesarean section harbor gut bacteria that resemble bacteria found on the skin.

Honey bees, in contrast, acquire their gut bacteria from both the surrounding environment and their social context — a phenomenon known as horizontal transmission. In a healthy colony, worker bees typically acquire their gut bacteria through interaction with microbes inside the hive, including fecal matter from adult bees. But the most likely route of microbiome transmission in queen bees is the “royal jelly,” a protein-rich food source produced by worker bees that is responsible for the development of queen bees during the larval stage. Unlike other bees, queens continue to feast on royal jelly through maturity, instead of the honey and “bee bread” that is consumed by workers.

The queen’s royal isolation from the dirt and grime of everyday life in the colony may account for the difference in her microbiome...